Delayed action door closer



Nov. 30, 1965 R. c. FLINT DELAYED ACTION DOOR CLOSER 3 Sheets-Sheet 1 Filed March 23, 1962 Nov. 30, 1965 R. c. FLINT 3,

DELAYED ACTION DOOR CLOSER Filed March 23, 1962 3 Sheets-Sheet 2 INVENTOR.

Nov. 30, 1965 R. c. FLINT 3,220,046

DELAYED ACTION DOOR CLOSER Filed March 25, 1962 5 Sheets-Sheet 5 /00 E6 02 72 40 6 //Z //0 m6 IN V EN TOR.

{ iwaez 0 1 1572 B United States Patent O 3,220,046 DELAYED ACTION DOOR CLOSER Russell C. Flint, Princeton, Ill., assignor to Schlage Lock Company, San Francisco, Calif., a corporation of California Filed Mar. 23, 1962, Ser. No. 181,957 Claims. (Cl. 1659) This invention relates to a door closer and more particularly to a delayed action door closer that will hold a door open for a predetermined period of time once the door has moved to its full open position. The invention further relates to a self-cleaning, regulatable check valve.

Under certain conditions, it is desirable that a door, once it has been opened, remain open for a short predetermined period of time to enable a person to pass through the door without manually holding it open. In hospitals, for example, it is often desirable that the doors have delayed action door closers in order that doctors, interns or nurses taking wheelchair patients from one area to another may open the door and then have sufficient time to wheel the patient through the door before it begins to close. It is, of course, desirable that the delayed action door closer be adapted such that it may readily be converted to a door closer without delayed action.

It is therefore an object of the present invention to provide an improved delayed action door closer.

It is a further object of the present invention to provide a delayed action door closer which may be adjusted to vary the time period in which the door stays open during a delayed action stage.

It is a further object of the present invention to provide a door closer which is adjustable to provide, if desired, delayed action door closing.

It is a further object of the present invention to provide an improved delayed action door closer which may be easily and inexpensively constructed.

It is a further object of the present invention to provide a self-cleaning, regulatable check valve.

It is a further object of the present invention to provide a self-cleaning, regulatable check valve which has partic ular utility in a delayed action door closer.

The invention, both as to its organization and method of operation, taken with further objects and advantages thereof, will best be understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a delayed action door closer embodying the features of the present invention mounted on a door and operatively connected to the head frame of a door frame;

FIGURE 2 is a longitudinal, top cross-sectional view of the delayed action door closer of FIGURE 1;

FIGURE 3 is a longitudinal, top cross-sectional view of the delayed action door closer of FIGURE 1, illustrating theposition of the piston and the paths of fluid travel as the door is being opened;

FIGURE 4 is a longitudinal, top cross-sectional view of the delayed action door closer of FIGURE 1, illustrating the position of the piston during the delayed action stage;

FIGURE 5 is an enlarged, partially cross-sectional view of the check valve embodying the features of the present invention; and

FIGURE 6 is a view of the check valve of FIGURE 5 taken along the line 66 of FIGURE 5.

Referring now to the drawings, and more particularly to FIGURE 1, the delayed action door closer of the present invention, referred to generally by reference numeral 20, is illustrated mounted on a door 22 and operatively connected to a head frame 24 of the door frame to which 3,22%,M6 Patented Nov. 30, 1965 "ice the door 22 is hinged. It is the function of the delayed action door closer 20 not only to control the speed with which the door 22 closes, but also, if desired, to hold the door 22 in its full open position for a predetermined length of time before the door 22 begins to close. The period in which the door 22 is being held in its full open position by the delayed action door closer 20 is hereinafter referred to as the delayed action stage.

To these ends, the delayed action door closer 20 permits the door to open in response to a person pushing or pulling the door 22. This is hereinafter referred to as the dooropening stage. Once the door has reached its full open position, depending upon the adjustment of the door closer 20, the door 22 may be made to be held open for a predetermined length of time or, in the alternative, may be allowed to immediately begin its closing operation. Once the door 22 begins to close, whether it be after a delayed action stage or not, the door closer 20 allows the door to close at a rapid or slow speed, as desired, until it has re turned relatively close to the door frame. This stage is hereinafter referred to as the general speed stage. After completing this stage, the door goes through the final stage of its closing operation in which it latches in the door frame.

During this final stage the door closer 20 will assure that the door 22 has sufiicient speed to properly latch, yet not enough speed to bang or slam into the door frame. Thus, if the door 22 during the general speed stage has been closing at a rapid rate, the door closer 20, in effect, breaks the speed of the door 22 to assure that it will not hang or 'slam into the door frame and yet properly latch, which is referred to hereinafter as the latching speed stage. On the other hand, if the door closer 20 has been set so that during the general speed stage the door 22 is closing very slowly, then the door closer 20 allows the door 22 to speed up sufficiently to assure proper latching, which is hereinafter referred to as the quick release stage.

The delayed action door closer 20 is mounted upon the door 22 by a bracket 26 and the operative cooperation between the door 22 and the delayed action door closer 20 is effected by a pair of arms 30 and 32 pivotally connected at 34. The free end of the arm 32 is attached to a rotatable shaft 36 extending from the delayed action door closer 20 and the free end of the arm 30 is pivotally attached to a mounting 38 secured to the head frame 24 of the doorframe. As the door 22 opens and the delayed action door closer 20 swings in an arc, the cooperative arrangement between the arm 30 and the arm 32 causes the arm 32 to rotate the shaft 36 relative to the delayed action door closer 20. Likewise, when the door 22 is being closed, the movement of the cooperating arms 30 and 32 will rotate the shaft 36 in the opposite direction relative to the delayed action door closer 20. In this arrangement, the shaft 36 must be rotated as the door 22 is opened or closed. Therefore, the delayed action door closer 20, by controlling the rotation of the shaft 36, controls the manner in which the door 22 is opened and closed and may hold the door 22 in its full open position for a predetermined period of time.

The manner in which the delayed action door closer 20 of the present invention controls the rotation of the shaft 36 and may be adjusted to hold the door 22 in its full open position for a predetermined length of time will be considered in more detail with reference to FIGURES 2-4. The delayed action door closer 20 includes a main body 46 having a transverse bore 42 and a longitudinally extending piston chamber 44 which communicates with the transverse bore 42. The outer ends of the piston chamber 44 are closed by screw plugs 46 or the like. Extending through the transverse bore 42 is the shaft 36 having a pinion 48. A spring (not shown) cooperates with the shaft 36 to constantly urge it and the pinion 48 to rotate in the door closing direction, i.e., in a clockwise direction when viewing FIGURES 2-4. The shaft 36 is suitably journalled and capped to prevent leakage of hydraulic fluid from the delayed action door closer 20. The end of the shaft 36 which extends outwardly from the delayed action door closer is, as discussed hereinbefore, connected to the arm 32.

Within the main body 40 and the longitudinal, circular cylindrical bore or piston chamber 44 is a piston 50 having piston heads 52 and 54 interconnected by a rack 56 having a plurality of gear teeth 57 in engagement with the pinion 48 on the shaft 36. In this manner, rotation of the shaft 36 and the pinion 48 will cause the rack 56 and the piston 50 to be correspondingly reciprocated or translated within the piston chamber 44.

The main body 40, including the piston chamber 44 and the transverse bore 42, is filled with hydraulic fluid, such as oil or an oil substitute. It is the control of the movement of the fluid within the piston chamber 44, as will be more apparent hereinafter, which assists the closer 20 in performing its intended functions.

The piston head 52 has a piston head passageway 58 extending longitudinally therethrough, its ends communicating with the piston chamber 44 on opposite sides of the piston head 52. A check or ball valve 60 is positioned within the piston head passageway 58. The check valve 60 is a one-way valve in that is prevents the flow of hydraulic fluid from left to right through the piston head passageway 58 when the piston head 52 is moving toward the left. On the other hand, when the piston head 52 is moving toward the right, the check valve 60 will allow fluid to flow through the passageway 58 from right to left.

It will be understood that any check valve which will perform the same function in substantially the same manner may be employed in place of the check valve 60.

Communicating with the left end of the piston chamber 44 is .a passageway 62 leading to a by-pass passageway 64 communicating with the bore 42. Also communicating with the piston chamber 44 and the by-pass passageway 64 is a passageway 66. The passageway 66 communicates with the piston chamber 44 at a point spaced longitudinally from the point at which the passageway 62 communicates with the piston chamber 44. Likewise, the passageway 66 communicates with the by-pass passageway 64 at a point spaced longitudinally from the point at which the passageway 62 communicates with the by-pass passageway 64.

' Within the by-pass passageway 64 there is positioned an adjustable dual needle valve, indicated generally by reference numeral 68. The dual needle valve 68 has therein a chamber 65 into which extends a rotatable, adjusting member 63. The chamber 65 communicates directly with the passageway 66. The adjusting member 63 has a plurality of longitudinal slots 94, one of which forms a variable orifice at 67 through which fluid from the passageway 62 must pass to enter the chamber 65. In addition, the adjusting member 63 has a groove therein forming an orifice 69 through which fluid from the chamber 65 must pass to reach the by-pass passageway 64. Both the orifice at 67 and the orifice 6? may be independently increased or decreased in size by rotating the adjusting member 63. In this manner, the needle valve 68 is adapted to control the flow of fluid from the passageways 62 and 66 to the by-pass passageway 64. The valve 68, in this instance, has been adjusted so that fluid flowing through the passageway 66 has a less restricted path of travel to the oy-pass passageway 64 than has the fluid flowing through the passageway 62 to the by-pass passageway 64, i.e., the orifice at 67 is smaller than the orifice 69.

7 Adjustable dual needle valves 68 are Well known in the Cir art and any valve which will achieve the same results as the valve 68 may be employed herein.

Communicating with the right end of the piston chamber 44 is a passageway 70 leading to a by-pass passageway 72 communicating with the bore 42. Also communicating with the piston chamber 44 and the by-pass passageway 72 is a passageway 74. The passageway 74 communicates with the piston chamber 44 at a point spaced longitudinally from the point at which the passageway 70 communicates with the piston chamber 44. Likewise, the passageway 74 communicates with the by-pass passageway 72 at a point spaced longitudinally from the point at which the passageway '70 communicates with the by-pass passageway 72. Sealing off one end of the by-pass passageway 72 is a regulatable check valve 76, which will be described in more detail hereinafter. At this juncture, it suffices to say that the check valve 76 allows fluid to flow freely from the passageway 70 to the by-pass passageway 72. On the other hand, the check valve 76 may be regulated or adjusted to control the amount of fluid which may pass from the by-pass passageway 72 through the valve 76 to the passageway 70 and the piston chamber 44.

The delayed action closer 20 is illustrated in FIGURE 2 when the door 22 is closed. When the door 22 is open, the shaft 36 and the pinion 48 are rotated against the force of the spring in a counter-clockwise direction, as shown in FIGURE 3, thereby translating the piston 56 toward the right in the piston chamber 44. As the door 22 is opened, the piston head 54 displaces hydraulic fluid from the right end of the piston chamber 44, this displaced hydraulic fluid passing to the left end of the piston chamber 44. .The solid arrows in FIGURE 3 illustrate the flow of fluid during this door-opening stage.

Specifically, as the door 22 is opening, the principal path of fluid flow will be from the piston chamber 44 through the passageways 74 and 70 to the by-pass passageway 72. The fluid thenenters the transverse bore 42 and will principally tend to flow through the passageway 58 and tie check valve 60 in the piston head 52 to the other side of the piston 50, since this is the path of least resistance. As the door 22 approaches the full open position the piston head 54 moves toward the right past the passageway 74. Once the piston head 54 closes or moves past the passageway 74, the displaced fluid flows through the passageway 79, the valve 76, the by-pass passageway 72 and the valve 60 to the left side of the piston head 60. FIGURE 3 specifically illustrates the flow of fluid during the door-opening stage when the piston head 54 has moved to the right past the passageway 74.

When the door 22 has moved to its full open position, the piston 50 is substantially in the same position illustrated in FIGURE 3. For the door 22 to close, the pinion 48 and shaft 36 must rotate in a clockwise direction as urged by the spring and the piston 50 move toward the left in the piston chamber 44. When the piston head 54 is to the right of the passageway 74, or blocking the passageway 74, and the check valve 76 has been adjusted to prevent or restrict the flow of fluid from the by-pass passageway 72to the passageway 70, the delayed action stage is in effect.

FIGURE 4 illustrates the door closer 2t and its piston 50 during a delayed action stage. It will be understood that for the piston 56 to move to the left fluid must be transferred from the left side of the piston head 52 to the right side of the piston head 54. In effect, the check valve 76 controls the delayed action stage since there are but two ways fluid may flow to the right side of the piston head 54; namely, through the check valve 76 and the passageway 70 or by seeping between the piston head 54 and the piston chamber 44. If the check valve 76 has been adjusted to close completely when fluid from the bypass passageway 72 tries to pass therethrough to. the passageway 70'(as shown in FIGURE 4) then the.

delayed action stage is of maximum duration since only that amount of fluid seeping around the piston head 54 passes to the piston chamber 44 on the right side of the piston head 54.

However, any shorter delayed action stage may be effected by adjusting the check valve 76 whereby a controlled amount of fluid may pass therethrough to the passageway 70 from the by-pass passageway 76. Once the check valve 76 has been so adjusted the seepage around the piston head 54 will generally become a negligible factor as the fluid will seek the flow path of least resistance.

From the more detailed discussion hereinafter of the valve 76 it will be understood how the amount of fluid flowing through the valve 76 to the passageway 70 may be regulated to control the length of time the door 22 is held in its full open position during the delayed action stage.

The delayed action stage terminates when the piston 50 has moved to the left sufficiently that the passageway 74 communicates with the piston chamber 44 on the right side of the piston head 54. At this point the general speed stage begins. During the general speed stage the check valve 60 in the piston head 52 closes and fluid is forced through the passageway 66 and the orifice 69 to the by-pass passageway 64. From the by-pass passageway 64 the fluid flows freely through the by-pass passageway 72 and the passageway 74 to the piston chamber 44 on the right side of the piston head 54.

As the piston head 52 blocks off the passageway 66, the door 22 enters the latching speed stage and is relatively close to the door frame. This is the stage in which the speed of the door is substantially reduced to prevent the door 22 from slamming into the door frame. During this stage the displaced fluid from the piston chamber 44 must flow through the passageway 62 and the orifice at 67 in the valve 68 to pass to the right end of the piston chamber 44. Since the orifice at 67 has been adjusted such that it is more diflicult for fluid from the passageway 62 to pass therethrough than it is for fluid to flow through the passageway 66 and the orifice 69 to the by-pass passageway 64, the door 22 will close at a slower rate during the latching speed stage. The latching speed stage continues as the piston head 52 moves past the passageway 66 and terminates when the door 22 is securely latched in the door frame.

It will be understood that the door closer 22 may be adjusted to achieve, among other things, a slow closing speed during the general speed stage such that it is necessary to increase the speed of the door 22 just before it reaches the door frame to assure proper latching, i.e., a quick release stage. This modification is achieved by adjusting the needle valve 68 such that the orifice at 67 is larger than the orifice 69. In this manner it is easier for fluid to flow through the passageway 62, the orifice at 67, and the chamber 65 to the passageway 66 than it is for fluid to flow through the passageway 62 and the orifice 69 to the by-pass passageway 64. This, of course, does not effect the door opening stage or the delayed action stage discussed hereinbefore. Nor is the flow path of the fluid altered during the general speed stage, except that the door 22 will close more slowly.

In this instance, the general speed stage continues until the piston head 52 has moved to the left past the passageway 66. Then the quick release stage begins, the flow of fluid during this quick release stage being through the passageway 62, the orifice at 67 and the chamber 65 to the passageway 66 and back to the other side of the piston head 52. From here the fluid will flow to the right side of the piston head 54 through the by-pass passageway 72 and the passageway 74. In this manner, the door 22 speeds up sufllciently during the quick release stage to assure proper latching.

Referring to FIGURES 5 and 6, the construction and operation of regulatable check valve 76 will be considered in more detail. The check valve 76 will be seen to comprise a valve seat member suitably secured by a press fit or the like within the by-pass passageway 72. The valve seat member 100 has an axially extending passageway forming chambers 102 and 104 interconnected by an orifice 106. A bevelled edge on the interior end of the chamber 102 forms a valve seat 108 for a ball 110 in the chamber 102.

An end plate 112 prevents the ball 110 from leaving the chamber 102 and is press fitted into an annular groove 114 in the end of the valve seat member 100 or otherwise secured thereto. As seen in FIGURE 7, the end plate 112 has an opening therethrough indicated generally by reference numeral 116. The opening 116 includes a circular opening 118 which has a diameter less than the diameter of the ball 110. Connected with the circular opening 118 are radially extending slots 120 which extend outwardly from the center of the opening 118 a distance greater than the radius of the ball 110. Preferably, opposing slots 120 should be aligned to insure that the distance between the ends of the opposing slots 120 is greater than the diameter of the ball 110. In this manner, the ball 110 may not block the opening 116 and prevent fluid from flowing out of the chamber 102.

A valve regulating member 122 extends into the chamber 104 of the valve seat member 100. The regulating member 122 is held in position by a bushing 124 which threadedly engages the housing 40. Suitable packing 126 is held by the bushing 124 against the valve seat member 100 and the valve regulating member 122 to prevent leakage of fluid around the valve regulating member 122. Through the threaded cooperation between the valve regulating member 122 and the bushing 124 the valve regulating member 122 may be rotated to move it into and out of the chamber 104.

The valve regulating member 122 has a cylindrical projection 128 concentrically aligned with the orifice 106. If the regulating valve member 122 is rotated sufliciently, it may be moved inwardly such that the projection 128 will prevent the ball 110 from seating upon the valve seat 108. Likewise, it will be understood that by adjusting the valve regulating member 122 the distance between the ball 110 and the valve seat 108 may be controlled.

. On the other hand, the valve member 122 may be rotated to move it outwardly such that the ball 110 will seat upon the valve seat 108 when fluid attempts to flow through the by-pass passageway 72 to the passageway 70. The valve seat member 100 has a radially extending passageway 130 which communicates with the chamber 104 and is positioned so as to communicate also with the passageway 7 0.

It will be understood that if fluid is attempting to move from left to right through the valve 76 to the passageway 70 the ball 110 will seat upon the valve seat 108 and preclude fluid flow therethrough in this direction unless the valve regulating member 122 has been rotated inwardly sufliciently that the projection 128 thereof prevents the ball 110 from seating on the valve seat 108, as in FIG- URE 5.

When the valve regulating member 122 has been adjusted as in FIGURE 5 to allow some fluid to flow from left to right through the valve 76, finely-divided solids, such as dirt, grit and the like, in the fluid may accumulate between the valve seat 108 and the ball 110. The more limited the fluid flow allowed through the valve 76 from the by-pass passageway 72, the smaller the passage between the ball 110 and the valve seat 108 and, accordingly, the more readily the finely-divided solids will accumulate. The accumulation of finely-divided solids on the valve seat 108 and the ball 110 may clog the valve 76 and thereby destory fine control of the fluid flow.

It is a feature of the check valve 76, however, that it is self-cleaning. This is effected when the flow of fluid is reversed, that is, fluid flows from the passageway 70 through the passageway 130, to the chamber 104, the

orifice 106 and the chamber 102 into the by-pass passageway '72. During such reverse fluid flow the ball 110 is forced away from the orifice 106. This permits the fluid to flow freely through the orifice 106 and also to pass over and around the ball 110. In this manner, any solids that have accumulated between the ball 110 and the valve seat 108 will :be removed by the free flowing fluid. The valve 76 is thereby cleaned automatically during reverse fluid flow.

The valve 76 is therefore particularly suitable for use in the delay action door closer 20 because every time the door 22 is opened fluid will be forced through the valve 76 in the reverse direction, i.e., from the passageway 70, and clean any finely-divided solids which may have accumulated between the ball 110 and the valve seat 108. Furthermore, such a valve 76 is advantageous in the delayed action door closer 20 since it may be finely adjusted to accurately control the duration of the delayed action stage.

While the embodiments described herein are at present considered to be preferred, it is understood that various modifications and improvements may be made therein, and it is intended to cover in the appended claims all such modifications and improvements as fall within the true spirit and scope of the invention.

What is desired to be claimed and secured by Letters Patent of the United States is: I

1. In a delayed action door closer having a fluid filled piston chamber and a piston sliding in said chamber in opposite directions during the opening and closing movements of a door to which the closer is connected, a bypass passageway communicating with the ends of said piston chamber, said by-pass passageway communicating through first and second spaced openings with the end of said piston chamber toward which said piston moves during said opening movements and thereby forming a fluid passageway between said openings, a valve in sa d fluid passageway allowing free flow of fluid through said fluid passageway during opening movements of said door and controlling the flow of fluid through said fluid passageway when said piston moves during closing of said door.

2. In the door closer of claim 1 wherein said valve is adjustable to vary the amount of fluid which may flow through said fluid passageway during closing of said door.

3. In a delayed action door closer having a fluid filled piston chamber and a piston sliding in said chamber in opposite directions during the opening and closing movements of a door to which the closer is connected, a bypass passageway communicating with the ends of said piston chamber, said by-pass passageway communicating with the end of said piston chamber toward which said piston moves during said opening movements through first and second passageways longitudinally spaced from one another, a valve in said by-pass passageway between where said by-pass passageway communicates with said first and second passageways, said valve allowing free flow of fluid through said by-pass passageway during opening movements of said door and closing said bypass passageway when said piston moves during closing of said door.

4. In a door closer of claim 3 wherein said valve may be adjusted to control the amount of fluid which flows therethrough during the closing movement of said door.

5. In a delayed action door closer having a fluid filled piston chamber and a piston sliding in said chamber in opposite direct-ions during the opening and closing movements of a door to which the closer is connected, two longitudinally spaced passageways communicating with the end of said piston chamber toward which said piston moves as said door is opening, said two passageways Cir communicating with a by-pass passageway whereby fluid passes from said piston chamber through said passageways to said by-pass passageway and to the other end of said piston chamber as said piston moves during the opening movements of said door, a valve in said by-pass passageway between where said passageways communicate with said by-pass passageway, said valve allowing fluid to flow freely therethrough during opening movements of said door and closing as said piston moves in the opposite direction during closing movements of said door.

6. In a delayed action door closer having a fluid filled iston chamber, a piston sliding in said chamber in opposite directions during the opening and closing movements of a door to which said closer is connected, said piston having first and second piston heads, and a bypass passageway communicating With the ends of said piston chamber, said by-pass passageway communicating with the end of said piston chamber toward which said piston moves during said opening movements through longitudinally spaced first and second passageways, a valve in said by-pass passageway between where said bypass passageway communicates with said first and second passageways, said valve allowing free flow of fluid through said by-pass passageway during opening movements of said door and closing said by-pass passageway when said piston moves during closing of said door, one of said piston heads having moved past one of said passageways during said opening movements of said door.

7. In a delayed action door closer having a fluid filled piston chamber, a piston sliding in said chamber in opposite directions during the opening and closing movements of a door to which said closer is connected, said piston having first and second piston heads, said first piston head having a passageway extending therethrough, means in said passageway in said first piston head allowing free flow of fluid through said passageway during opening movement of said door and closing said passageway in said first piston head when said piston moves during closing movements of said door, a by-pass passageway communicating with the ends of said piston chamber, said by-pass passageway communicating with the end of said piston chamber toward which said piston moves during opening movements of said door through longitudinally spaced first and second passageways, a valve in said by-pass passageway between where said first and second passageways communicate with said bypass passageway, said valve allowing fiuid to flow freely through said by-pass passageway as said door is being opened and closing said by-pass passageway when said piston moves during closing of said door, said second piston head moving past one of said first and second passageways when said door is in full open position.

8. In the door closer of claim 7 wherein said valve may be adjusted to control the amount of fluid which flows therethrough during the closing movement of said door.

9. In the door closer of claim 8 wherein said by-pass passageway has a second valve therein, said second valve controlling the movement of said piston as said door is closing after said second piston head has moved sufliciently that it no longer is past one of said first and second passageways.

10. In the door closer of claim 7 wherein said valve comprises a valve seat member forming a first and second chamber interconnected by an orifice, said first chamber having an open end communicating with said by-pass passageway, a ball in said first chamber which will seat therein to close said orifice when fluid enters said first chamber from said by-pass passageway, a valve regulating member extending into said second chamber which may be axially moved therein to prevent said ball from seating in said first chamber, said second chamber having an outlet communicating with said first passageway, said 9 1 0 second piston head moving past said second passageway 1,833,121 11/ 1931 Norton 16-5 1 when said door is in full open position. 0,991 5/ 1957 Schlage 16-62 2,810,571 10/1957 Ferguson 6t a1. 18888.51 References Cited by the Examiner ,8 ,039 7/ 1959 Nickels 137513.5 5 2,962,046 11/1960 Bochan 137-5 13.5

UNITED STATES PATENTS 1 01 2 2 1912 Regan 16 59 DUNLEY J. STOCKING, Primary Examiner.

1,770,250 7/ 1930 Norton 16-59 BERNARD A, GELAK, Examiner. 

1. IN A DELAYED ACTION DOOR CLOSER HAVING A FLUID FILLED PISTON CBAMBER AND A PISTON CLIDING IN SAID CHAMBER IN OPPOSITE DIRECTIONS DURING THE OPENING AND CLOSING MOVEMENTS OF A DOOR TO WHICH THE CLOSER IS CONNECTED, A BYPASS PASSAGEWAY COMMUNICATING WITH THE ENDS OF SAID PISTON CHAMBER, SAID BY-PASS PASSAGEWAY COMMUNICATING THROUGH FIRST AND SECOND SPACED OPENINGS WITH THE END OF SAID PISTON CHAMBER TOWARD WHICH SAID PISTON MOVES DURING SAID OPENING MOVEMENTS AND THEREBY FORMING A FLUID PASSAGEWAY BETWEEN SAID OPENINGS, A VALVE IN SAID FLUID PASSAGEWAY ALLOWING FREE FLOW OF FLUID THROUGH SAID FLUID PASSAGEWAY DURING OPENING MOVEMENTS OF SAID DOOR AND CONTROLLING THE FLOW OF FLUID THROUGH SAID FLUID, PASSAGEWAY WHEN SAID PISTON MOVES DURING CLOSING OF SAID DOOR. 